Lock.



DAVID H. PINGREE, 0F MELROSE, MASSACHUSETTS.

Lock. 7

Specification of Letters Patent.

Patented Mar. 12, 1918.

Application filed June 23, 1917. Serial No. 176.576.

T 0 all whom it may concern:

Be it known that 1, DAVID H. PrNonnn, a citizen of the United States,and a resident of Melrosc, in the county of Middlesex and Commonwealthof Massachusetts, have invented certain new and useful Improvements inLocks, of which the following is a full, clear, and exact specification.

The purpose of this invention is the construction of a key-actuated lockwherein the key, after the bolt has been thrown from the inside of theapartment, cannot be pushed in from the outside and a skeleton key usedfor opening the door. Another result of my invention is the effecting ofmeans whereby the locking of the door automatically closes the key-holeagainst prying eyes.

In carrying my invention into efiectI provide the bolt of the lock witha plate which screens the key hole when the bolt is thrown, therebyshutting olf vision through the hole and preventing the key from beingpushed in from the outside of the door.

Referring to the drawings forming part of this specification, Figure 1is an elevation of a lock embodying my improvement, a part of the casebeing broken away to eX- pcse the interior. Fig. 2 is an elevation ofthe lower part of the same. Fig. 3 is a' sect onal View on the line X-Xin Fig. 1. Fig. 4 is a perspective view of the bolt alone, having mydevice formed thereon.

The lock upon which my improvement is shown as applied is of a wellknown construction, comprising a case composed of two separable sections1 and 2, keyholes 3 and 4 and a bolt 5. From the bolt descends a finger6 preferably integral therewith, and disposed to be close beside theline joining the two keyholes, when the bolt is in its unlockedposition. Rigid with the lower end of this finger is an elbow 7 passingbeneath the level of the keyholes and terminating in an angular plate 9,the latter being arranged to be outside the range of the keyholes whenthe bolt is in its unlocked position, but to be brought therein when thebolt is thrown to its locked position, as indicated by Fig. 2.

Consequently, when the door is unlocked, the plate or guard 9 is out ofthe way of the keyhole, and the key can be inserted and removed withoutinterference; so also after the key has been inserted from the outsideof the apartment, the key can be freely removed after locking the door;but after the key has been introduced from within and the bolt thrown,the guard 9 comes between the ward of the key and the inner keyhole 3,and the key can no longer be withdrawn.

It is, of course, not desirable to provide a guard as 9 for the outerkeyhole i, inasmuch as then the key could not be removed when lookingthe door from the outsde; and it is no drawback to have the keyincapable of removable after locking the door from the inside, forpractically all people leave the key in the lock at such times.

I prefer to form the guard 9 with a wing 10 positioned to remain closebeside the range of the keyholes after the bolt has received its lockingthrow, as an aid in unlocking the door from the outside. 1 fter the keyhas been inserted, it cannot be turned in the wrong direction, as ispossible with similar locks not given my improvement, but themanipulator immediately notes he can turn the key in but one direction,and that the correct one.

As shown in Fig. 2, the presence of the guard 9 in the range of thekeyholes after locking the door, entirely closes the same to anyinquisitive eye.

A further advantage derived from the wing 10 is the hindrance therebygiven to picking the lock by means of a bent wire. If it were not forthis wing, the key could be turned from the outside to carry its wardtoward the right, as viewed in Fig. 2, and thereby leave a clear spacefrom the key hole to the bolt and its ward; but by providing the wing10, the key cannot be turned backward, and if it is turned oppositely itremains a barrier between the keyhole and the bolt efiectually stoppingthe passage of a wire to the bolt.

What I claim is:

1. A lock comprising a case having a keyhole, and a bolt formed with adownwardly extended finger, a horizontal elbow projecting from the lowerend of said finger below said keyhole, and a guard-plate rising from thesaid elbow, the plate and finger being spaced to stand at opposite sidesof the keyhole when the bolt is in its unlocked posh ing therefrom belowthe level of the key- Copies of this patent may be obtained for hole,and a Winged plate rising from the extremity of said elbow.

In testimony that I claim the foregoing 10 invention, 1 have hereuntoset my hand this 20th day of June, 1917.

DAVID H. PINGREE.

five cents each, by addressing the Commissioner of Patents,

Washington, D. C.--'

